title: [The possible mechanisms of alkaline phosphatase and alpha-amylase immobilization in dental enamel].
abstract: The kinetic method revealed that by the rate of adsorption on apatite, serum alkaline phosphatase (AlP) is homologous and salivary AlP consists of two fractions: "slow" with the constant of adsorption rate approximating that of serum AlP and "fast" with 5-6 times greater constant. A mechanism of phosphatase immobilization on apatite by two-stage sequential reaction is proposed. The constants of rates of both stages for the serum phosphatase and fast salivary fraction are determined. Difference of the products of both stages by the Michaelis constant (KM) is demonstrated for the fast fraction. The KM of the second-stage immobilization product is close to that of AlP immobilized on dental enamel, which confirms the hypothesis about their identity. In contrast to AlP, both serum and salivary alpha-amylase react with apatite at the same rate and, probably, by the same mechanism as the bulk of salivary and serum protein.
authors.forename: M Iu
authors.initials: MIu
authors.lastname: Zhitkov
authors.forename: V K
authors.initials: VK
authors.lastname: Leont'ev
mesh_terms: D000327:Adsorption; D000469:Alkaline Phosphatase / Q000378:metabolism*; D003743:Dental Enamel / Q000201:enzymology*; D017886:Durapatite; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D007700:Kinetics; D010316:Particle Size; D012463:Saliva / Q000201:enzymology; D000516:alpha-Amylases / Q000378:metabolism*
chemical_list: D004800:Enzymes, Immobilized; D007527:Isoenzymes; D017886:Durapatite; D000469:Alkaline Phosphatase; D000516:alpha-Amylases
vernacular_title: Vozmozhnye mekhanizmy immobilizatsii shchelochnoĭ fosfatazy i al'fa-amilazy na émali zubov.